Document feeding device and method for assembling document feeding device

ABSTRACT

The present invention provides a document feeding device whose components are easily assembled. A document feeding device includes a housing base unit and a drive unit, the housing base unit forming a document transportation path, and including a roller shaft including a roller and a driven gear, the drive unit transmitting power to the roller shaft, and including a drive gear meshing with the driven gear, and when the drive unit is mounted in the housing base unit, the drive gear being positioned on an upper or lower side of the driven gear to mesh with the driven gear.

The present invention relates to a document feeding device and a methodfor assembling a document feeding device.

BACKGROUND ART

PTLs 1 to 3 are Patent Literatures disclosing a document feeding device.

FIG. 8 is a diagram illustrating a configuration of a document feedingdevice of the related technique. The document feeding device includes ahousing base unit 4 and a drive unit 6.

FIG. 9 is a diagram illustrating a configuration of the drive unit 6 inthe document feeding device of the above-mentioned related technique.The drive unit 6 includes a motor 1, a drive transmission system 2, anoutput shaft 3, and a control device 5.

A main function of the document feeding device is to feed documents oneby one and cause the documents to pass through a reading unit at aconstant speed. This function is implemented by transmitting the powerof input shaft corresponding to the motor 1 to the output shaft 3 by thedrive transmission system 2. The drive transmission system 2 isconstituted by transmission members such as gears and belts. A form anda quantity of the gears and the belts are appropriately changed so as toachieve a transporting speed of a document corresponding to a readingspeed of the device. As the output shaft 3, a rubber roller is attachedto the roller shaft with a driven gear. For the roller of the outputshaft 3, a driven roller making a pair exists, and via friction betweenthis pair of rollers, a document is transported. The number of rollersused as the output shaft 3 is rarely one, and a plurality of rollers areusually used in combination. There are various applications andfunctions of the rollers thereof. The roller, for example, includes apaper feeding roller that feeds documents one by one, a reading rollerthat plays a role of stable document transportation near the readingunit, and a paper discharging roller that is provided in front of apaper output tray, and drives out a document, and the like.

Sharing a mounting space, such various constituent elements areincorporated inside the device, mainly in the housing base unit 4 thatforms a document transportation path.

Assembling of the drive unit 6 forming a transmission path includes workof regularly arranging a large quantity of gears to be directed to aplurality of output shafts, and work of arranging the control device 5at an intermediate position of the transmission path and performingharness processing, which causes difficulty in assembling. A fault inthe assembling work generates irregularity in transmission of the driveunit 6, and the irregularity of this transmission leads directly tononuniformity in a read image. In other words, precision in transmissionof the drive unit 6 directly influences reading quality of a document sothat highly precise assembling is required.

In the document feeding device illustrated in FIG. 8 and FIG. 9, work ofmounting, from the horizontal direction, gears in the laterally longhousing base unit 4 forming the document transportation path isstandard. In other words, first, one (“a” in FIG. 9) of two side platesof the drive unit 6 is attached to the housing base unit 4, andrespective roller shafts are fixed. Next, gears are attached to therespective roller shafts, and are sandwiched and fixed by the other oneside plate (“b” in FIG. 9). This is mounting in the members receivingthe output shaft rollers, and for this reason, can be regarded as highlyprecise component mounting.

CITATION LIST Patent Literature

[PTL 1] Japanese Laid-open Patent Publication No. 2012-180217

[PTL 2] Japanese Laid-open Patent Publication No. 2009-182949

[PTL 3] Japanese Laid-open Patent Publication No. 2004-026500

SUMMARY OF INVENTION Technical Problem

The following problem, however, exists in the document feeding deviceillustrated in FIG. 8 and FIG. 9. In other words, the work of mounting,from the horizontal direction, gears in the laterally long housing baseunit 4 forming the document transportation path lacks in efficiency inthat the work has to be performed with the laterally long housing baseunit being kept standing upright, or the like. Further, an additionaljig such as a jig for holding the housing standing upright is needed forperforming this work.

An object of the present invention is to provide a document feedingdevice and a method for assembling a document feeding device, whichsolve the above-described problem.

Solution to Problem

A document feeding device according to the present invention is adocument feeding device including a housing base unit and a drive unit,wherein the housing base unit forms a document transportation path, andincludes a roller shaft including a roller and a driven gear, the driveunit transmits power to the roller shaft, and includes a drive gearmeshing with the driven gear, and when the drive unit is mounted in thehousing base unit, the drive gear is positioned on an upper or lowerside of the driven gear to mesh with the driven gear.

A method for assembling a document feeding device according to thepresent invention is a method for assembling a document feeding deviceincluding a housing base unit and a drive unit, wherein the housing baseunit forms a document transportation path, and includes a roller shaftincluding a roller and a driven gear, the drive unit transmits power tothe roller shaft, and includes a drive gear meshing with the drivengear, and when the drive unit is mounted in the housing base unit, thedrive gear is positioned on an upper or lower side of the driven gear tomesh with the driven gear, the method including a step of mounting thedrive unit in the housing base unit from an upper or lower direction atthe time of the meshing.

Advantageous Effects of Invention

According to the present invention, it is possible to provide a documentfeeding device and a method for assembling a document feeding device, inwhich components are easily assembled.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic diagram illustrating a configuration of a documentfeeding device 10 according to a first exemplary embodiment.

FIG. 2 is a perspective view illustrating external appearance of adocument feeding device 20 according to a second exemplary embodiment.

FIG. 3 is an exploded perspective view illustrating a configuration of ahousing base unit 210 of the document feeding device 20 according to thesecond exemplary embodiment.

FIG. 4 is a schematic diagram illustrating arrangement of respectiverollers of the document feeding device 20 according to the secondexemplary embodiment.

FIG. 5 is a diagram illustrating a configuration of a drive unit 220 ofthe document feeding device 20 according to the second exemplaryembodiment.

FIG. 6 is a schematic diagram illustrating a configuration of thedocument feeding device 20 according to the second exemplary embodiment.

FIG. 7 is an exploded perspective view illustrating a configuration of adocument feeding device 30 according to a third exemplary embodiment.

FIG. 8 is a diagram illustrating a configuration of a document feedingdevice of the related technique.

FIG. 9 is a diagram illustrating a configuration of a drive unit 6 ofthe related technique.

DESCRIPTION OF EMBODIMENTS Example 1

FIG. 1 is a schematic diagram illustrating a configuration of a documentfeeding device 10 according to a first exemplary embodiment, in whichthe left side illustrates a front of the device, and the right sideillustrates a side of the device.

The document feeding device 10 is configured to include a housing baseunit 110 and a drive unit 120.

The housing base unit 110 forms a document transportation path, andincludes as an output shaft a roller shaft 113 provided with a roller111 and a driven gear 112.

The drive unit 120 transmits power to the roller shaft 113, and includesa drive gear 121 meshing with the driven gear 112.

The drive gear 121 meshes with the driven gear 112, and has a functionof transmitting power to the roller shaft 113 provided with the drivengear 112. Being positioned on an upper side of the driven gear 112, thedrive gear 121 meshes with the driven gear 112 when the drive unit 120is mounted in the housing base unit 110.

In assembling operation, the drive unit 120 is mounted in the housingbase unit 110 from an upper side of the housing base unit 110.

According to the document feeding device 10 of the first exemplaryembodiment, when the drive unit 120 is mounted in the housing base unit110, the drive gear 121 is positioned on an upper side of the drivengear 112 to mesh with the driven gear 112. This enables the drive unit120 to be mounted in the housing base unit 110 from the upper side. As aresult, the document feeding device whose components are easilyassembled can be provided.

Modified Example

Preferably, when the drive unit 120 is mounted in the housing base unit110, the drive gear 121 is positioned on an obliquely upper side of thedriven gear 112 to mesh with the driven gear 112. Additionally, an angleθ made by a horizontal plane and a line connecting a center of the drivegear 121 to a center of the driven gear 112 in FIG. 1 is preferablyequal to or smaller than 45 degrees. Thereby, compared with a case wherethe drive gear 121 is positioned on the just upper side of the drivengear 112 to mesh with the driven gear 112, for example, collisionbetween teeth of the gears at the time of assembling can be alleviated,and the gears easily mesh with each other.

Although the configuration is made such that the drive unit 120 ismounted in the housing base unit 110 from an upper side in the abovedescription, the same advantageous effect can be obtained even by aconfiguration in which the mounting is performed in the same manner froma lower side. In other words, the housing base unit 110 may be attachedto the drive unit 120 from an upper side. The angle θ in this case ispreferably equal to or smaller than 45 degrees from a horizontal planeto a lower side.

Example 2

The document feeding device 20 according to the second exemplaryembodiment is configured to include a housing base unit 210 and a driveunit 220, similarly to the document feeding device 10 according to thefirst exemplary embodiment.

FIG. 2 is a perspective view illustrating external appearance of thedocument feeding device 20. FIG. 3 is an exploded perspective viewillustrating a configuration of the housing base unit 210 of thedocument feeding device 20. FIG. 4 is a schematic diagram illustratingarrangement of respective rollers when viewing from a roller-axisdirection. The arrow in FIG. 4 schematically indicates a path throughwhich a document is transported.

The housing base unit 210 is configured to include roller shafts 213provided with rollers 211 and driven gears 212. The rollers 211 includea paper feeding roller 201, a separating roller 202, a reading roller203, and a paper discharging roller 204. The driven gears 212 includedriven gears 202 a, 203 a, and 204 a. In other words, the driven gears202 a, 203 a, and 204 a are provided at end portions of the respectiveroller shafts provided with the separating roller 202, the readingroller 203, and the paper discharging roller 204.

As for attachment of the respective roller shafts to the housing baseunit 210, a general method is used so that the description is omittedhere.

The paper feeding roller 201 is arranged at an upper center of thedocument feeding device 20, and on a lower side of the paper feedingroller 201, the separating roller 202 making a pair with the paperfeeding roller 201 is arranged. The paper feeding roller 201 has afunction of sending out a document to a document transportation path.

The separating roller 202 has a function of receiving drive of rotationopposite to that of the paper feeding roller 201, and taking offdocuments one by one from a sheaf of documents. Since this function is ageneral function, the description is omitted here. Further, a pickroller playing an auxiliary role for the paper feeding roller 201 isadopted in some cases, but the description is omitted here.

It is assumed that a side of inserting a document is an upstream side,and a side of discharging a document is a downstream side.

At least one end of the roller shaft of each of the paper feeding roller201, the separating roller 202, the reading roller 203, and the paperdischarging roller 204 is fixed to the housing base unit 210. In FIG. 3,the roller shafts 213 are drawn on the upper side of the housing baseunit 210, but actually, only the paper feeding roller shaft ispositioned on the upper side of the housing base unit 201, and the otherroller shafts are positioned on the lower side of the housing base unit.

The housing base unit 210 includes a positioning part 214 b and adrive-unit fixing screw hole 214 c for attaching the drive unit 220. Thepositioning part 214 b and the drive-unit fixing screw hole 214 c areeach provided at two positions by taking into consideration rotationprevention and vertical positioning, and have a shape corresponding tothe drive unit. This makes it possible to precisely mount the drive unit220 in the housing base unit 210 from the upper side.

The housing base unit 210 forms a guide surface 214 a on the downstreamside of the paper feeding roller 201, and forms a documenttransportation path in cooperation with an unillustrated guide surfaceon the upstream side.

The reading roller 203 is arranged on the downstream side of thetransportation path. A new transportation path is formed so as to make aU-turn around the reading roller 203. The transportation path is forcedto make the U-turn so that a region on the lower side of the waitingdocuments before paper feeding can be used as a document dischargespace, and the device can be downsized. As illustrated in FIG. 4, at thereading roller 203, one or two pairs of driven rollers 203′ forming aset with the reading roller 203 are arranged on the circumference. Thereading roller 203 has a function of transporting a document at theU-turn part by a pressure to and from the driven roller 203′.

At a position where a document reaches the lowest point in the deviceafter completion of the U-turn of the document, a reading unit 215 isarranged. The reading unit 215 includes a reading device 215 a and atransparent glass 215 b. The transparent glass 215 b functions as aguide of the reading unit 215, and a document passes between the readingdevice 215 a and the transparent glass 215 b. The reading units 215 maybe provided on a front side of and on a rear side of a document,respectively so that both surfaces of a document may be readsimultaneously.

On the downstream side of the reading unit 215, the paper dischargingroller 204 is arranged. The paper discharging roller 204 has a functionof discharging and driving off a document having been read.

On the downstream side of the paper discharging roller 204, a paperoutput tray 216 is provided.

FIG. 5 is a diagram illustrating a configuration of the drive unit 220.The drive unit 220 is constituted by a motor 222 and a case-shaped formthat includes two side plates 280 a and 280 b as frames. The case-shapedform includes the necessary number of drive gears (gear group) 221, andgear shafts inside. The gear group 221 and the gear shafts areinterposed between the both side plates 280 a and 280 b so that rigidityand shaft precision can be secured. As a result, high accuracy of a readimage can be achieved. As a material of the side plates 280 a and 280 b,sheet metal can be selected to secure the rigidity and the shaftprecision.

In the document feeding device illustrated in FIG. 8 and FIG. 9, apartfrom the above-described problem, when the gears are attached from thehorizontal direction to the respective roller shafts, and are fixed bythe side plate b of the drive unit 6, it was necessary to slide the sideplate b while paying attention so that each gear is not displaced. Inaddition, a jig for sliding the side plate b was needed. On thecontrary, in the document feeding device 20 according to the presentexemplary embodiment, the drive unit 220 is made case-shaped. Thereby,the single unit is formed, and the drive unit superior in handling canbe provided.

The gear group 221 includes three drive gears (preceding gears) 205,206, and 207 meshing with the driven gears 202 a, 203 a, and 204 aprovided at the respective separating, reading, and discharging rollershafts.

FIG. 6 is a schematic diagram illustrating a configuration of thedocument feeding device 20, in which the left side of FIG. 6(a)illustrates a device front, and the right side illustrates a side. Asillustrated in FIG. 6(a), when the drive unit 220 is mounted in thehousing base unit 210, the gear group 221 is positioned on the upperside of the driven gears 212 to mesh with the driven gears 212. In otherwords, as illustrated in FIGS. 6(b 1) to (b 3), each of the drive gears205, 206, and 207 is positioned on the upper side of the correspondingdriven gear 212 to mesh with the driven gear 212.

The gear group 221 is preferably positioned on an obliquely upper sideof the driven gears 212 to mesh with the driven gears 212 when thedriven unit 220 is mounted in the housing base unit 210. Further, inFIGS. 6(b 1) to (b 3), angles α, β, and γ made by a horizontal plane andlines connecting centers of the gear group 221 (205, 206, and 207) tocenters of the driven gears 212 are preferably equal to or smaller than45 degrees.

Thereby, compared with a case where the gear group 221 (205, 206, and207) is positioned on the just upper side of the driven gears 212 tomesh with the driven gears 212, for example, collision between teeth ofthe gears at the time of assembling can be alleviated, and meshingbetween the gears is facilitated.

A motor 222 has a function as a drive source. When electric power issupplied to the motor 222, the drive unit 220 transmits drive to thegear group 221. The drive is transmitted to the roller shafts 213 viathe driven gears 212 meshing with the gear group 221.

According to the document feeding device 20 of the second exemplaryembodiment, when the drive unit 220 is mounted in the housing base unit210, the gear group 221 is positioned on the upper side of the drivengears 212 to mesh with the driven gears 212. Thereby, the drive unit 220can be mounted in the housing base unit 210 from the upper side. As aresult, it is possible to provide the document feeding device whosecomponents are easily assembled.

Example 3

For a configuration that is not particularly described in the following,a document feeding device 30 according to a third exemplary embodimenthas the same configuration as the document feeding devices 10 and 20according to the first and second exemplary embodiments.

FIG. 7 is an exploded perspective view illustrating the configuration ofthe document feeding device 30.

In the document feeding device 30 according to the present exemplaryembodiment, an electromagnetic clutch 323 is provided in a transmissionpath to a paper feeding roller 301. The electromagnetic clutch 323 isincluded in the drive unit 320, and is positioned coaxially with a paperfeeding roller shaft 301 a when the drive unit 320 is mounted in thehousing base unit 310. Electromagnetic clutches are illustrated in FIG.2 and FIG. 5 as well.

The electromagnetic clutch 323 has a function of electrically making onand off action for drive transmission. In the present exemplaryembodiment, the electromagnetic clutch 323 is used for controlling driveand stop of the paper feeding roller 301.

At the paper feeding roller shaft 301 a, an attachment 317 is provided.An attachment is illustrated in FIG. 2 and FIG. 3 as well. Theattachment 317 divides the paper feeding roller shaft 301 a into a shaftwhere the paper feeding roller 301 is provided and a shaft where theelectromagnetic clutch 323 is provided. Thereby, while the shaft towhich the electromagnetic clutch 323 is attached is kept fixed to thedrive unit 320, the shaft where the paper feeding roller 301 is providedcan be freely attached and detached. As a result, the paper feedingroller 301 is an independent unit that can be periodically replaced inmaintenance or the like. Also in an assembling process, it is possibleto incorporate the paper feeding roller 301 alone later, withoutinfluencing the housing base unit 310 and the drive unit 320.

According to the paper feeding device 30 of the third exemplaryembodiment, the attachment 317 is provided at the paper feeding rollershaft 301 a. Thereby, the shaft that is positioned at an upper part ofthe device and is prone to be an obstacle to assembling, i.e., the shaftwhere the paper feeding roller 301 is provided can be incorporated alonelater. As a result, it becomes possible to mount the drive unit 320 inthe housing base unit 310 from an upper side.

Although the exemplary embodiments of the present invention aredescribed above, the present invention is not limited to theabove-described exemplary embodiments, and needless to say, includesother modified examples and applied examples without departing from theintention of the present invention.

The invention of the present application claims a priority based onJapanese patent application No. 2013-140579 filed on Jul. 4, 2013, whoseentire disclosure is incorporated herein.

INDUSTRIAL APPLICABILITY

The present invention can be applied to a document feeding device suchas a printer, a copying machine, or a facsimile machine.

REFERENCE SIGNS LIST

10, 20, 30 document feeding device

110, 210, 310 housing base unit

111, 211 roller

112, 212 driven gear

113, 213 roller shaft

120, 220, 320 drive unit

201, 301 paper feeding roller

202 separating roller

203 reading roller

203′ driven roller

204 paper discharging roller

202 a, 203 a, 204 a driven gear

205, 206, 207 drive gear

214 a guide surface

214 b positioning part

214 c drive-unit fixing screw hole

215 reading unit

215 a reading device

215 b transparent glass

121 drive gear

221 gear group

222 motor

280 a, 280 b side plate

301 a paper-feeding-roller shaft

317 attachment

323 electromagnetic clutch

1 motor

2 drive transmission system

3 output shaft

4 housing base unit

5 control device

6 drive unit

a, b side plate

What is claimed is:
 1. A document feeding device comprising a housingbase unit and a drive unit, wherein the housing base unit forms adocument transportation path, and comprises a roller shaft including aroller and a driven gear, the drive unit transmits power to the rollershaft, and comprises a drive gear meshing with the driven gear, and whenthe drive unit is mounted in the housing base unit, the drive gear ispositioned on an upper or lower side of the driven gear to mesh with thedriven gear.
 2. The document feeding device according to claim 1,wherein when the drive unit is mounted in the housing base unit, thedrive gear is positioned on an obliquely upper or obliquely lower sideof the driven gear to mesh with the driven gear.
 3. The document feedingdevice according to claim 1, wherein when the drive unit is mounted inthe housing base unit, the drive gear is positioned on an upper or lowerside of the driven gear at an angle of 45 degrees or less from anhorizontal plane with respect to the driven gear to mesh with the drivengear.
 4. The document feeding device according to claim 1, wherein thehousing base unit comprises a positioning part and a drive-unit fixingscrew hole used for mounting the drive unit, and the positioning partand the drive-unit fixing screw hole have a shape corresponding to thedrive unit.
 5. The document feeding device according to claim 1, whereinthe roller shaft includes a separating roller shaft, a reading rollershaft, and a paper discharging roller shaft, and the drive unitcomprises drive gears meshing with driven gears provided at therespective roller shafts.
 6. The document feeding device according toclaim 1, wherein the drive unit comprises two side plates, and the drivegear is interposed unitedly between the two side plates.
 7. The documentfeeding device according to claim 1, wherein the housing base unitcomprises as the roller shaft a paper feeding roller shaft including apaper feeding roller and the driven gear, the drive unit comprises anelectromagnetic clutch controlling drive and stop of the paper feedingroller, the electromagnetic clutch is positioned coaxially with thepaper feeding roller shaft when the drive unit is mounted in the housingbase unit, and an attachment is provided at the paper feeding rollershaft, and divides the paper feeding roller shaft into a shaft where thepaper feeding roller is provided and a shaft where the electromagneticclutch is provided.
 8. A method for assembling a document feeding devicecomprising a housing base unit and a drive unit, wherein the housingbase unit forms a document transportation path, and comprises a rollershaft including a roller and a driven gear, the drive unit transmitspower to the roller shaft, and comprises a drive gear meshing with thedriven gear, when the drive unit is mounted in the housing base unit,the drive gear is positioned on an upper or lower side of the drivengear to mesh with the driven gear, and at the time of the meshing, thedrive unit is mounted in the housing base unit from an upper or lowerside.
 9. The method for assembling the document feeding device accordingto claim 8, wherein the housing base unit comprises as the roller shafta paper feeding roller shaft including a paper feeding roller and thedriven gear, the drive unit comprises an electromagnetic clutchcontrolling drive and stop of the paper feeding roller, theelectromagnetic clutch is positioned coaxially with the paper feedingroller shaft when the drive unit is mounted in the housing base unit, anattachment is provided at the paper feeding roller shaft, and via theattachment, the paper feeding roller shaft is divided into a shaft wherethe paper feeding roller is provided and a shaft where theelectromagnetic clutch is provided.